British actor Sam Kelly, star of comedy series Allo 'Allo and Porridge, has died at the age of 70.

The Manchester-born actor's agent, Lynda Ronan, said Kelly died peacefully Saturday morning after a long illness. He was reported to have been admitted to a hospice on Friday.

She said: "He does not leave any family but a host of friends who were his chosen family. His death is a great loss to them and the profession."

Former Doctor Who actor Colin Baker, who attended the London Academy of Music and Dramatic Art with Kelly in the 1960s, paid tribute to his colleague on Twitter. "Cannot believe that lovely Sam Kelly has died," he wrote. "We were at drama school together – lovely, funny, talented chap. So sad."

A tribute also came from film and TV actor Phil Davis, who said: "So sad to hear that Sam Kelly has died, a wonderful actor, a proper gent and one of the funniest men I ever had the pleasure of working with."

Kelly played prisoner Bunny Warren in the BBC's Porridge between 1974 and 1978 and Nazi captain Hans Geering in the first four series of Allo 'Allo between 1982 and 1987. As Captain Geering he was best remembered for his cry "tler!" – an unenthusiastic salute to Hilter.

His other roles include the sitcoms Barbara and On the Up, as well as the 1993 prisoner of war TV comedy Statagluft, in which he played Hitler alongside Stephen Fry and Nicholas Lyndhurst.

Upon reports of Kelly's death, Fry tweeted: "Very saddened to hear about Sam Kelly's death. He played a splendid Hitler".

Throughout his career Kelly also received plaudits for his theatrical performances which included roles at the National Theatre and Old Vic. In February he withdrew from his part as the Wizard of Oz in the hit West End play Wicked due to ill health.

Jacqueline Hughes, who starred with Kelly in Wicked, paid tribute on Twitter, writing: "So terribly saddened by the death of Mr Sam Kelly. I feel so lucky to have had the chance to work with such an inspiring gentleman xxx"

Other friends and colleagues also expressed their sadness at Kelly's death. Natalie Anderson from the TV soap Emmerdale said: "Totally devastated to hear of the sad news of my friend and 'Wizard' Sam Kelly's passing!!! A truly wonderful and incredible gentleman!"

And writing on Twitter before he was about to go on stage in the West End stage show Dirty Rotten Scoundrels, Robert Lindsay, star of Citizen Smith and My Family, said he would dedicate the performance to Kelly.

He said: "Feel so depressed about the amazing Sam Kelly's passing how do we manage a second comic musical tonight? we dedicate it to him RIP".

Sherlock actor Mark Gatiss said: "Desperately sad news that the wonderful Sam Kelly has left us. Such a funny, talented man and one of the good guys. RIP Bunny Warren".

Comedy actress Rebecca Front, star of The Thick Of It, tweeted that Kelly was a "lovely actor".